1. Field of the Invention
The present invention relates to an information processing device, a squealing sound generation method in the information-processing device, and a computer program product. More particularly, the present invention relates to an improvement of an artificial sound generation technology in a simulation game device on which one can play a game, such as a car race or Time Attack, as a driver of a vehicle within a virtual three-dimensional space.
2. Description of Related Art
There has been provided a simulation game device on which a player can play a car race, Time Attack, or other driving game as a driver of a virtual vehicle within a virtual three-dimensional space. Such a game device has games where a player can have a realistic excitement by skidding and crashing the virtual vehicle in accordance with the driving situations. Also, the sound effects of various artificial sounds produced according to the driving situations can bring further realistic excitement (see, for example, Patent Document 1).
The sound includes the engine sound, and shrill frictional noise that is generated when a tire violently skid when the vehicle accelerates suddenly, brakes suddenly, and makes a sharp turn (so-called “squealing sound”, such as screeching and squeaking noises, that can be expressed in onomatopoeia). Conventionally, the squealing sounds in driving games were generated with a loop tone or single tone, while changing the pitches of the pre-registered tones as necessary, in accordance with the degree of frictional force between the tires of a virtual vehicle and the road surface.
[Patent Document 1] Japanese Patent Laid-open Publication No. H10-137445